1. Field of the Invention
The present invention relates to a terminal device, a wireless device wirelessly communicating with such a terminal device and a wireless communication system including such a terminal device and wireless device.
2. Description of the Related Art
Techniques have been proposed to use 802.15.4 sensor motes that consume less power than wireless local area network (LAN) cards to observe a wireless LAN channel that is at the same frequency and, when a terminal detects a radio wave from a transmitter, to wake up the wireless LAN card of this terminal (Nilesh Mishra, Kameswari Chebrolu, Bhaskaran Raman, Abhinav Pathak: Wakeon WLAN, WWW 2006).
Further, a technique has been proposed to use a wake-up receiver that consumes still less power to wake up a wireless LAN card (JP 2007-526655 A, WO 04/100503, U.S. Pat. Pub. No. 2007/0253468, and Shigemi Ishida, Makoto Suzuki, Takashi Morito, Hiroyuki Morikawa: A Multi-step Wake-up Scheme for Low-Power-Listening Wireless Communication System, IEICE technical report, IN2007-218, p. 355-360, March 2008).